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  1. #14
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    Quote Originally Posted by ga-hvac-tech View Post
    Is this open or closed loop???

    If closed loop... sounds like the loop is too small...
    It's a closed loop

  2. #15
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    Sep 2019
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    Quote Originally Posted by 1-Hvacdoc View Post
    Sounds like long run times with too short off time for loop to cool down or poor ground contact with loop. Also check glycol level.
    This was essentially the diagnosis from the installer. They said they are 100% that the loop lost its grout, probably due to earth shifting and a crevice opening. It sounded improbable to me, but here we are.

    They are sending a crew out tomorrow (on my dime) to start digging to determine the state of the grout and whether adding new grout is an option or whether we're drilling a new loop.

    If anyone has any other ideas beforehand let me know. Especially if they are less than the $1,200/day excavator rate.

  3. #16
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    Aug 2009
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    Beatrice, NE
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    At 100 loop temps you are not moving enough water/transferring heat from the loop. I had an issue with my loop with 100 loop temps and they came back and regrouted some loops. This seems to have helped my issue however at 14 GMP and a 4T unit I think you are short on water flow also. There should be a chart that shows acceptable in/out differential rates. My guess is your differential is too high which is helping to raising your loop temps.

  4. #17
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    Quote Originally Posted by BNME8EZ View Post
    At 100 loop temps you are not moving enough water/transferring heat from the loop. I had an issue with my loop with 100 loop temps and they came back and regrouted some loops. This seems to have helped my issue however at 14 GMP and a 4T unit I think you are short on water flow also. There should be a chart that shows acceptable in/out differential rates. My guess is your differential is too high which is helping to raising your loop temps.
    Thanks for this. Can you tell me what the process looked like with the regrouting / how long it took? They are expecting to come dig tomorrow as an exploratory dig -- should they be ready to regrout on the same day?

    With regard to the flow rate and differential, I will pass along the thought to the dealer. Is that something that can be adjusted or is it a characteristic of the loop? To my sophomoric understanding flow rate seems like it would be a function of the pump itself and the diameter of the plumbing.

  5. #18
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    Aug 2009
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    Beatrice, NE
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    In my situation I had them do horizontal boring and they didn't go as deep as I wanted. They dug up the manifold pit and could see the where some of the bore holes were open. They had a pipe they shoved into the holes and started pumping grout till it was coming out of the holes. It had been grouted the first time around but apparently the grout ran out a crack before it set up. It took them a little over a half a day. Yours may take longer if it was vertical as your holes will be 10' or so apart so it would take longer to dig up. My pit is only about 4x6.

    Sometimes it can be adjusted sometimes it is dependent on the pump/piping. One other factor is loop piping size. Some people thing bigger is better where as smaller tubes will yield more turbulance for better heat transfer. The pump should have been sized to meet the flow needs of the loop and equipment.

  6. #19
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    Sep 2008
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    VA
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    I don't think our well guys even use grout or glycol here. We hit water aquifers everywhere and the ground is saturated below 10'. Also, the ground doesn't freeze below 6". We do verticle 210' depth loops.
    "The only true wisdom is in knowing you know nothing" Socrates

  7. #20
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    Quote Originally Posted by eurekasprings View Post
    Unknown. I think derived from pressure drop because I didn't see a flow meter.
    That's an acceptable method going by the mfg. pressure drop charts, but they should log all of the data in order to benchmark, especially if you're having an ongoing issue.
    "The only true wisdom is in knowing you know nothing" Socrates

  8. #21
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    Quote Originally Posted by mgenius33 View Post
    I don't think our well guys even use grout or glycol here. We hit water aquifers everywhere and the ground is saturated below 10'. Also, the ground doesn't freeze below 6". We do verticle 210' depth loops.
    It can freeze here down to 4' sometimes a little more if there is lack of snow cover, so we have to use a none toxic antifreeze like a RV antifreeze. Even at that the bore holes have to be grouted to prevent any leakage from entering the water table.

  9. #22
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    Sep 2019
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    So the installer came out with the backhoe and air compressor on trailer on Monday and Tuesday. Pics at https://imgur.com/a/OizgCad

    They dug to the loop and used the compressor to blow gravel out of the casing.

    I was pretty surprised about how uncoordinated the process was, the installer had to throw in the towel early on day 1 because the rubber tubing out of the compressor was flexing too much for him to get good effect on the bore hole. He had to bring a few sticks of steel piping on day 2 to craft himself a stiff tool to get down in there.

    The loop got lacerated in the process (they said flying gravel sliced it open .. facepalm). But the bigger issue is they can't break through beyond about 30 ft. I don't know if earth shifted or if gravel got wedged during the blowing process. It seems to me the loop would have been pinched and not flowing if earth shifted sufficiently, but I'm pretty uneducated about these things.

    I do find it a little strange that they selected the most active spot on the property to drill (under the gravel drive). Is that common?

    Their recommendation now is that I take a mulligan and drill new wells, or rip out the heat pump and install a traditional AC unit. After coughing up the dough for the dig here of course.

    I had some concerns about the process of abandoning the current wells (don't we need to grout them to the top anyway to avoid contaminating my ground water?) and got to clicking around on the state's well water construction committee website to find the installer isn't a licensed driller, so at this point I'm wondering about the quality of the advice I'm getting from them. Planning to call a company that is licensed for a second opinion here, but wanted to post the update and ask if anyone's dealt with similar. Thanks for all the time and thought you've spent already.

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